English
Production of Rare Sugar (D-allulose) from Waste Paper Using Enzymes Derived from Various Microbial Strains
Hansol Park1,*, Eun Jin Cho1, Gyeong-min Yoon2, Hyeun-Jong Bae1,2
1 Bio-energy Research Center, Chonnam National University, Gwangju, Republic of Korea
2 Department of Convergence Food Biotechnology, Chonnam National University, Gwangju, South Korea, 61186
Corresponding author: baehj@chonnam.ac.kr
Approximately two billion tons of waste paper are generated annually worldwide, accounting for the second-largest fraction of municipal solid waste (MSW). The accumulation of waste paper poses significant environmental challenges, including landfill saturation and the generation of harmful by-products during incineration. Since paper is produced from wood through chemical and mechanical pulping processes that remove most lignin, it contains a relatively high cellulose content compared with other lignocellulosic biomass, making it a promising feedstock for biorefinery applications.
Meanwhile, growing concerns regarding obesity and excessive sugar consumption have increased interest in alternative sweeteners. Among them, D-allulose, a rare sugar with low caloric value, has attracted considerable attention due to its physiological benefits, including antioxidant activity and inhibition of fat accumulation.
In this study, the enzymatic hydrolysis efficiency of waste paper substrates, including office paper and newspaper, was improved through physical pretreatment. The glucose released from the hydrolyzed waste paper was subsequently used for the production of D-allulose. Glucose was first converted to fructose using xylose isomerase from Enterocloster bolteae 90B8, followed by epimerization to D-allulose using D-allulose 3-epimerases derived from Agrobacterium tumefaciens, Ruminiclostridium cellulolyticum, and Pseudomonas cichorii. Among the tested substrates, the highest D-allulose conversion rates reached approximately 42% from office paper and 41% from newspaper.
These results demonstrate that waste paper can be effectively valorized as an inexpensive lignocellulosic feedstock for the production of high-value rare sugars. This study highlights the potential of integrating waste paper recycling with enzymatic bioconversion as a sustainable strategy for resource recovery and biorefinery development.
